APOE and Mental deterioration: While those with the APOE ε4/ε4 genotype had more stage N3 time, stage N3 was not associated with cognitive decline in MrOS [72], even after adjustment for APOEε4 statusConsistent with increased stage N3 time among ε4/ε4 genotype carriers, the APOE ε4/ε4 genotype was also associated with higher sleep efficiency and decreased WASO, indicating overall less arousability.